Automotive muffler



June 27, 1961 w. H. POWERS 2,990,028

AUTOMOTIVE MUFFLER Filed April 1, 1955 2 sheets-sheet 1 June 27, 1961 w. H. PowERs AUTOMOTIVE MUFFLER 2 Sheets-Sheet 2 Filed April l, 1955 IN V EN TOR. e 7' /7./ )ya were'.

I BY

MJ F n raf/14576.

MSN W United StatesPatent ice 2,990,028 AUTOMOTIVE MUFFLER Walter H. Powers, Jackson, Mich., assignor, by mesne assignments, to Walker Manufacturing Company, Racine, Wis., a corporation of Delaware Filed Apr. 1, 1955, Ser. No. 498,638 11 Claims. (Cl. 181-36) The invention relates to muiers and, in particular, to muers used to silence t-he exhaust stream of automotive internal combustion engines.

It is an object of this invention to provide a muiler construction of the dual ilow type.

Another object of this invention is to provide a muffler that is adapted to be arranged transversely of the length of an automobile. f

The invention accomplishes these and other objects by means of a mufer construction in which the opposite ends of the elongated mufer casing are each provided with an inlet and an outlet. Special silencing constructions are provided within `the muffler casing and these are connected to the inlets and communicate the gas owing from the inlets to the outlets. Preferably, the two inlets will be connected to different banks of lengine cylinders so that the pulses of gas owing therein will be out of .phase with each other; and, inthe mufliers shown and described herein, the silencing structure' includes chambers that are common to both inlets so that the gases may interminglev and tend to level out the pulses and pressure waves.

The invention is illustrated in the accompanying drawings which show preferred embodiments thereof and in which:

FIGURE 1 is a diagrammatic representation of an exhaust system showing the present muflier arranged transversely of the length of the car;

FIG. 2 is a longitudinal cross section through one embodiment of mufer constructed in `accordance with the invention;

. IFIG. 3 is an end view taken from the left of FIG. 2;

FIG. 4 is a cross section taken along the line 4-4 of FIG. 2;

FIG. 5 is a -longitudinal section on line 5-5 of FIG. 6

.through a modified form of muiiier embodying principles of this invention; and

FIG. 6 is a section on line 6-6 ofFIG. 5.

FIGURE l shows diagrammatically a typical V-8 engine 1 having the twin banks of cylinders 3 and 5 which furnishk exhaust to the exhaust lines 7 and 9, respectively. The lines 7 and 9 are connected to a mufer M which is transverse of the lengt-h of the automobile, as will be recognized by its position in FIG. 1. Tail pipes 11 and 13 `are connected to the mufer M and exhaust gases from the mui-ller which have been silenced in it. v

Turning now to the form of muier M which is shown in FIGS. 2*-4, the muflier 21 has an oval shape casing 23 with heads 25 and 27 (sometimes called headers) that close the opposite ends of the casing and which are interlapped at 29 with the ends of the casing to provide a leak-tight construction. The head 27 has an outwardly directed flange or. neck 31 which defines an opening that receives an inlet tube 33 which is in gas-ti-ght connection with the'exhaust line 7.` The end lhead,2 5 has an outwardly turned flange or neck 35 which provides an opening to receive an inlet bushing 37 that is in gastight communication with the exhaust line 9.

Inside of the casing k 23 land reading ifrom left to right are a series of transverse'partitions'which have anges bent parallel to the casing 23 `and in contact with the inner wall of the casing 23. These partitions are identified, respectively, by

the reference numerals 39 through 46 and all of them are securely spot welded in position to the mutiler cas- Patented June 27, 1961 ing 23. The partitions 40-46 are provided, respectively', with flanged openings adjacent the top portion thereof, these llanged `openings or necks being identified by the reference numerals 47 through 53, lrespectively. Fitted in the openings 47-50 of the partitions 40-43 is an `im,- perforate tube 54 and it -may be spot welded to each one of the flanged necks 47-50 as indicated. 'I'he tube 54 is in alignment with the inlet tube 33 and receives and supports a slightly turned down end section 55 of the inlet tube. The inlet tube 33 extends through the openings 51-53 of the partitions 44-46, aswell as through the opening 50 of the partition 43, -and may be spot welded to the necks of these partitions as shown in the drawings. At the outer end the tube 33 is expanded or increased in diameter as indicated by the beads and intermediate land 57 so that the tube will tightly t the outwardly turned neck 31 and permit spot welding of the tube to the neck 31 after the internal parts have been Iassembled. 4It will be seen that the tube 33 acts as a force transmitting member `which ties the head 27 to the internal parts of the muler which in turn are welded to the casing so that ample support for the head 27 against blowout is provided.

At the other end of the mufer, the inlet bushing 37 lits in a anged neck 59 of an aligned opening in partition 39 `and is spot welded to the neck 59. The bushing 37 is expanded as shown at 61 into proper contact with the liange 35 ofthe header 25 so` that the spot rwelding can be done after the bushing has been spot 'welded to the partition 39 and the internal parts assembled. With this arrangement it will be seen that the partition 39 and the header 25 are tied together in force transmitting relationship by the bushing 37 which is spot welded to each one of these members. The space between the partition 39 and the partition 40 constitutes a crossover chamber 63. Leading away from the chamber 63 is a tube 65, the opposite ends of the tube 65 being spot welded to the outturned flanges 67 and 68 of the partitions 40 and 43, respective-ly. It may be noted here that the partitions 39, 40, 43, and 44 tit the periphery of the casing 23 all lthe way around while the intermediate partitions .41, 42, 45, and 46 tit most of the periphery but do not tit the bottom part thereof as shown by Ithe shape of the partition 42 in FIG. 4. Returning to the construction of tube 65, the tube is provided with circumferentially spaced embossments 70 which t in necks or flanged openings 69 and 71 in the intermediate partitions 41 and 42 and provide means for spot welding the tube to the partitions, such tubes and embossments being described in Patent 2,251,369. The tube 65 is directly in line with the inlet bushing 37 and in addition to carrying the gas from bushing 37 it also carries cross-over gas ,from chamber 63 into a cross chamber 73 which is provided in the casing 23 between the partitions 43 and 44. Directly in h'ne with the tube65 is an imperforate reduced diameter tube that is mounted in and spot welded to the lianged openings 77-7 9, respectively, of the partitions 44, 45, and 46. The tube 75 projects into a chamber l81 ydefined in the casing 23 between the partition 46 and the header 27. It will be recognized thatv the chamber 8,1 constitutes a tuning or resonator chamber and that the tube 7'5 is the sole inlet and outlet to this chamber. In viewof the dead-end nature of the tube 75 and chamber 81, gas in the cross chamber 73 must flow either to the left or right through the tubes 83 or 85, respectively` The inside ends of the tubes 83 and 8S are supported in and spot Welded to inturned anges87 and 89, respectively, of the partitions 43 and 44 while the outermost endsof the tubes 83 and 85 `are supportedin the outlet bushings 91 and 93, respectively, which inftuifjn p are connected to the tail pipes 13 and 11, respectively. The bushing 91 is spot welded to an inturned neck' or ange 95 in the partition 39 and is expanded and spot welded at 97 to an outturned neck or flange '99 on the header 25. It will be seen that the outlet bushing 91 acts .in the same manner as the inlet bushing 37 to tie the head 25 and the 4partition 39 together. In addition, the outlet tube 83 may be spot welded to the bushing .91.. .The outlet 'tube`85 is spot welded at 101 to the out- 'plet'bushing 93 and the bushing 93 is expanded and spot welded to the outturned neck 103 of the head 27 so it will be seen that the bushing 93 acts to tie the head 27 to the internal parts and transmit load on the head to the internal pants in the same manner as described in connection with the inlet tube 33.

vSurrounding the greater portion of the length of the Voutlet .tube 813 is a cylindrical shell 105 which is spot Welded to the semicircular bottom ilange portions 107 and 109 of the partitions 41 and 42, respectively, and iits'into the narrow bottom end of the easing, preferably in contact therewith as seen in FIG. 4. As in the case of the tube 65 the outlet tube 83 is lock seamed along its length and provided with circumferentially spaced embossments 111 (like 70) which t in flanged necks L12-115, respectively, of partitions 116419, respectively, which are spot welded inside of the casing 105 to provide a series of spit chambers or high frequency chambers 121, 122, and 123 surrounding the tube 83. The tube 83 is l.provided with louvers 125 of a type which cause the gas `gas from the exhaust line 7 will enter the tube 33 and pass along its length until it reaches the cross-over chamber `63 at the end of tube 54 which is in alignment with the vinlet tube 33. Between the partitions 44 and 45 is a chamber 127 and between the partitions 45 and 46 is `a chamber 129, these chambers being relatively large volume spit chambers and the inlet tube 33 is provided with slots or other suitable perforations or louvers 131 .so that gas can flow into the chambers 127 and 129, `respectively, it being noted that the chamber 129 is somewhat larger than the chamber 127 and will therefore act on somewhat lower frequencies. Between the partitions 40, 41, 42, and 43 are a series of spit chambers 133, 134, and 135, of which the chamber 135 is the smallest and the chamber 134 is the largest in volume. The tube 65 A.has louvers 136 formed therein of the type adapted to `cause the gases to swirl circumferentially around the outside of the tube `65 and this communicates the gas within the `tube 65 with the spi-t chambers 133, 134, and 135, this comprising the gas that has entered the muiiler at the inlet 33 and owed along the length of the muler as well as the gas thathas entered directly from the inlet 37. Glas leaving the tube 65 iiowsinto the cross chamber V73 and if desired the inlet tube 33 may be provided with aseries of apertures -1317 within the chamber 73 to permit .some bypass of gas from the tube 33 directly into the chamber 73. Some of the gas reaching the chamber '73 will ilow directly along the length of the tube 75 into ,the resonator chamber 81 and it will be recognized that this Idesign is such |as to control the heavy and sustained vpower notes. Gas and sound waves are mixed up and intermingled in the chamber 73 and will ow either to the left or the right through the outlet tubes 83 and 85, and while passing through these tubes will be subjected `to the high frequency tuning action of the spit chambers 121-123 and 121 to 123', from whence the gases will 'ow through the outlet bushings 91 and 93 into the tail r.pipes 13 and `11 `and thence to atmosphere. It is also within the purview ofthe invention to provide openings Vpipe 11.

4 in tube `54 and partition 39 so as to vary the sound attenuating characteristics ofthe mufer.

Turning now to the modilied form of muffler shown in FIGS. 5 and 6 which is identified by the reference number 201, the mufller is provided with an oval shaped casing 203 of suitable vconstruction and having leftand rightah-and yend heads 205 and 207 that are connected in a leakproof manner to the ends of the casing 203. The muler 201 has an elbow-shaped Vinlet fitting 209 which connects with the exhaust line `9 and a second inlet elbow 211 at the other end which connects with the exhaust line 7. The muiiler 201 has an outlet elbow 213 which connects with the exhaust tail pipe 13 and an outlet elbow 215 Vat the other end which connects with the tail It will be understood that the elbow shaped inlets and outlets 209, 211, 213, and 215 are shaped to adapt themselves to the physical requirements of a par ticular automobile and 'that they can be modified as desired without changing the eiectiveness of the internal parts to be described hereafter in silencing the exhaust gases. In other Words the inlet and outlet nipple and bushing construction can be modilied to suit the particular job. Within the casing 203 are two flanged transverse partitions 217 and 219 which are spot welded around their flanged peripheries to the inside of the shell 203. Between the partitions 217 and 219 is a crossover chamber 221. With one exception which will be pointed out hereinafter, the structure between the partition 217 and the head 205 is identical to the structure between the partition 219 and the head 207, hence only the structure to the left of the partition 217 be described and the similar structure on the right of the partition 219 has the same reference number with a `prime aixed thereto. Between these partitions and the end heads 205 and 207 are Ian additional pair of partitions 223 and 225 which are spot Welded around their flanged peripheries to the inside of the shell 203. The-partitions are provided with |a series of aligned flanged openings or necks 227, 228, and 229, respectively, which pass the inlet tube 231. The inlet tube 231 is spot welded to the necks 227 and 229 and it may be of the lock seam construction and provided with `spaced circumferential ernbossments 233 whereby it may also be spot welded to the flange 228 of the partition 225. Surrounding the part of the tube 231 between the partitions 225 and 217 are a pair of complemental sheet metal stampings 235 and 236 which are necked down at their opposite ends 23611 and inner center portion 236b to engage the tube 231 yand which have flanges that are spot welded together so that the stampings 235 and 236 define a pancake com struction providing twospit chambers 237 and 238 around the tube 231.

The outlet tube arrangement is substantially identical to the inlet tube arrangement and may include the outlet tube proper 241 which is spot welded to the neck 243 of the partition 223 and the neck 245 of the partition 217. The tube 241 may also be of the lock seam construction and be formed with spaced circumferential embossments 247 whereby the tube may be readily spot welded to the neck 249 around lan opening in partition 225. A pancake construction comprising complementa! semicircular anged shells 251 and 253 surrounds that portion of the tube 241 which is between the partitions 225 and 217, the flanges 255 of the shells 251 and 253 being spot welded together .and the shells being necked down yat 257 to engage and be mounted upon the tube 241. A .partition 259 divides th space between the transverse partitions 223 and 225 into a pair of spit chambers 261 and 263 communicating respectively through suitable slots, louvers, or other openings 265 Iand 267 with the inlet tube 231 and the outlet tube 241. The inlet tube 231 rhas suitable slots, louvers, or openings 269 formed therein which open'into-the spit chambers 237 and 238 while the outlet tube has suitable slots, louvers, or apertures 271 formed therein which open into the spit chambers 273 and 275 formed by the pancakes 251 and 253. The space between the partitions 225 and 217 constitutes a relatively large closed volume resonator chamber 277 and the gases and sound waves reach it from the crossover chamber 221 through a tuning tube 278 which is spot welded to a anged opening or neck 279 in the partition 217 and also spot welded at a point 281 to the pancake 235. The space between the partition 223 and the end head 205 (or 207) constitutes a second and somewhat smaller volume resonator chamber 283. The crossover chamber 221 is connected to the chamber 283 by a tube 285 that is supported in and spot welded to flanged openings 286, 287, and 288 in the partitions 223, 225, and 217. Y Ihe tube 285 is imperforate and it will be noted that the tube 285 is somewhat smaller diameter than the tube 285, this constituting the sole difference between the left-hand muffling structure and the righthand muiing structure with respect to the cross-over chamber 221.

In operation the gases enter the inlet elbows 209 and 211 and since these elbows are connected to opposite banks of cylinders the pulses will be somewhat out of phase and will tend to equalize and even out when they meet in the central chamber 221. The gases pass through the inlet tubes 231 and 231 Vand some of the higher frequency noises are taken out by the spit chambers 261, `2.37, and '238, The gases that have entered the central chamber 221 are free to leave through either the outlet passage 241 or the outlet passage 241 and thence pass through the outlet elbows 213 and 215 to the tail pipes 13 and 11, respectively. In passing through the outlet tube 241 (and of course the outlet tube 241') the gas and sound waves will be subjected to the action of the high frequency or spit chambers 275, 273, and 263i. The heavier notes of lower frequency will pass through the tubes 278 or 285 into the resonator chambers 277 and 283 (and 277 `and 283'). It will be seen that the construction of the silencing arrangement within the muifler 201 provides four big and eight small spit chambers as Well as four resonator or tuning chambers which could, if desired, be tuned to four diiferent notes. The muiiier is therefore capable of treating a wide range of frequencies and noises and therefore of giving a very effective job of removing noise from the exhaust streams.

llt will now be realized that the invention has provided a transverse muflier construction which is adapted to be placed in a strategic position underneath an automobile especially adjacent the rear end thereof where more space is available for such a construction, Itis also adapted to receive gas in a dual now arrangement and Ito intermingle out of phase pulses so as to tend to even out the gas ow. It will be apparent that modifications can be made in the structure that has been selected for illustration herein without departing from the principles and scope of the invention.

I claim:

1. An exhaust system for an internal combustion engine having twin banks of cylinders comprising, an exhaust line connected to and leading gases away from one bank of cylinders and a second exhaust line connected to and leading exhaust gases away from said second bank of cylinders, said exhaust lines being of substantially equal length and running parallel to each other, a muler extending transversely to said exhaust lines and having inlet means at opposite ends connected respectively to said rst and said second exhaust lines, said muffler having a common mixing chamber located centrally thereof, inlet pipes of substantially equal length within said muffler connected respectively to said ytwo inlet means and extending between said inlet means and said mixing chamber and emptying into said mixing chamber whereby the distance of gas travel from each of said banks into said chamber is substantially equal, and outlet means for conducting the exhaust gases away from said mufller.

2. In a muier construction, an elongated hollow cas.-

6 ing having heads `at each end sealing off the ends of the casing, each of said heads having an inlet therein, each of said heads having an outlet therein, and gas passage and silencing means within said casing connecting each of said inlets to both of said outlets, said last named means including a common chamber located centrally within said casing, means providing two resonator chambers within said casing on opposite sides of said chamber, and four tubes connecting said common chamber to said resonator chambers, said gas passage means extending through and being imperforate in said resonator chambers, there being no inlet and outlet to said resonator chambers except as provided by said four tubes. y3. In a muffler, an elongated sheet metal casing, heads at opposite ends of said casing and rigidly secured thereto, each of said heads having an inlet tube therein, said inlet tubes being spot welded to said heads, each of said heads having an outlet tube therein, each of said outlet tubes being spot welded to said heads, internal partitions and tubes within said casing 4and rigidly secured by spot welding to said casing, the inside ends of both said inlet tubes and both said outlet tubes being spot welded to said internal partitions.

4. In a dual inlet-dual outlet muffler construction, an elongated sheet metal casing having closed ends, an inlet located at each end of said casing, an outlet located at each end of said casing, a pair of longitudinally spaced transversely extending partitions centrally located at a medial position within said casing and defining between them a common cross chamber, axially aligned inlet tubes connecting each of said inlets to said cross chamber, axially aligned outlet tubes connecting said cross chamber to each of said outlets, a pair of axially spaced partitions located between each of said central partitions and the adjacent ends of the casing to define a chamber between one of said partitions and the end of the casing, a second chamber between one of said partitions and said medial partition, and a third chamber between said two partitions constituting said pair, said first and second chambers constituting resonator chambers and said third chamber constituting a spit chamber, means connecting said inlet and outlet tubes to said spit chamber, and means individually connecting said first and third resonator chambers to said cross chambers.

5. The invention set forth in claim 4 including pancake structures mounted around the inlet and outlet tubes in said second chamber and defining with said tubes a pair of spit chambers.

6. The invention set forth in claim 5 including longitudinal partition means in said third chamber dividing it into a spit chamber for the inlet tube and a spit chamber for the outlet tube.

7. In a muler construction having a pair of inlets and a pair of outlets, an elongated sheet metal casing closed at opposite ends, means within said casing defining a medially located cross chamber, tubes connecting each of said inlets to said cross chamber, means providing a series of spit chambers around the tubes which connect said inlets to said cross chamber, means dening a pair of resonator chambers on opposite sides of said cross chamber, tubes of different lengths connecting said cross chamber to said resonator chambers, outlet tubes connecting said cross chamber to said outlets, and means providing a series of spit chambers around said outlet tubes.

8. The invention set forth in claim 7 wherein certain of said spit chambers around said tubes are provided by pancake constructions, certain of said tubes connecting said cross chamber to said resonator chambers being spot welded for support to said pancake construction.

9. A mulfler construction comprising an elongated hollow casing having closed ends, a pair of longitudinally spaced partitions extending transversely across the interior of said casing and respectively forming with said closed ends end chambers at each end of the casing, inlet and outlet conduits in said casing and extending to the outside thereof, each of said end chambers having a said conduit extending through it, a second lpair of longitudinally separated partitions extending transversely across the interior of said casing and located between said rst mentioned partitions and forming with said rst mentioned partitions a pair of intermediate chambers and a .central chamber, gas passage means supported on said partitions and connecting said inlet conduits to said central chamber but terminating outside of said central chamber so that there is gas flow through the volume of said central chamber, gas passage means supported on said partitions connecting the central chamber with said outlet conduits, and means providing for admission of sound and gas to said intermediate chambers.

10. A lmuiiier construction comprising an elongated casing having closed ends, a pair of partitions extending transversely across the interior of said casing and located respectively adjacent closed ends thereof and defining with said closed ends `closed resonator chambers, an inlet and an outlet conduit at each end of the casing extend- `ing through said closed chambers and each being rigidly lsecured to the adjacent said partitions, said conduits each being imperforate within said closed chambers, and gas passage and silencing means within the casing between said partitions interconnecting said inlet conduits and said outlet conduits and providing for ow and silencing of gas through the casing, and tuning necks provided in said partitions.

11. In a muffler construction having a pair of inlets and a pair of outlets, an elongated sheet metal casing closed at opposite ends, means Within said casing Idefining a medially located cross chamber, tubes connecting each of Said inlets to said cross chamber, 'means defining a pair of resonator chambers located respectively on opposite sides of said cross chamber, tubes of different lengths connecting said cross chamber to said respective resonator chambers, and outlet tubes connecting said cross chamberto said outlets.

References Cited in the le of this patent UNITED STATES PATENTS 1,781,503 Ford Nov. 11, 1930 2,078,420 Sheldrick Apr. 27, '1937 2,151,470 Hollerith Mar. 21, 11939 2,357,792 Powers Sept. 5, 1944 2,489,585 Necchi Nov. 29, V1949 2,618,355 Hedrick Nov. 18, 1952 2,658,580 Trembley Nov. 10, 1953 2,692,025 Maxim Oct. 1'9, A1954 FOREIGN PATENTS 49,795 Switzerland Feb. 2, `1910 187,171 Great Britain Oct. '19, 1922 481,480 Great Britain Mar. 11, 1938 506,100 Belgium Oct. '15, 1951 

